1. Field of the Invention
The present invention relates to an optical disc device and a control method for the optical disc device, and is applicable to an optical disc device for recording and reproducing data on and from an optical disc, such as a CD-R. More particularly, the present invention intends to make it possible to confirm whether data can be correctly reproduced, with a simple construction while effectively avoiding a reduction of the data transfer rate, by suppressing changes in signal level caused upon boosting of the laser power of a laser beam and detecting the presence of defects on an optical disc based on the result of detecting a return light corresponding to a sub-beam spot used for tracking control, which is formed on the preceding side with respect to scan of a main beam spot used to form pits or marks for recording of the data. Also, the present invention intends to make it possible to confirm whether data can be correctly reproduced, with a simple construction while effectively avoiding a reduction of the data transfer rate, by suppressing changes in signal level caused upon writing of the data and determining whether the recorded data and address data can be correctly reproduced, based on the result of detecting a return light corresponding to a sub-beam spot used for tracking control, which is formed on the succeeding side with respect to scan of a main beam spot used to form pits or marks for the recording of the data.
2. Description of the Related Art
Hitherto, in an optical disc device for recording and reproducing data on and from an optical disc, such as a CD-R (Compact Disc Recordable), a CD-RW (Compact Disc Rewritable) and DVD-R (Digital Video Disc Recordable), the so-called verifying operation has been required after the end of recording by, for example, accessing a recorded area again for the purpose of confirming that the recorded data is correctly reproduced.
More specifically, an optical disc device generally executes such a confirming process in two stages of, after recording data in predetermined amount, accessing the recorded area again to reproduce the data and determining a reproduced result. In this connection, the following method is also proposed. Based on a confirmation result, a retry is executed as required. An area, in which data cannot be correctly reproduced even after repeating such a retry, is determined to be a defective area. Then, with the so-called alternative process, the data is recorded in another area other than the defective area.
According to another proposed method, the confirming process and the recording process are simultaneously executed in parallel by arranging two optical pickups, i.e., one for recording and the other for reproducing, recording desired data with the recording pickup, and at the same time reproducing the data, which has been just recorded, with the reproducing pickup. As an alternative method for simultaneously executing the confirming process and the recording process in parallel, it has been further proposed to provide a defect detecting mechanism on an optical pickup and to detect defects with the defect detecting mechanism.
However, the above-described conventional methods have problems as follows. With the method of, after recording data in predetermined amount, reproducing the recorded data and determining a reproduced result, two recording and reproducing processes are alternatively repeated in recording of continuous data, thereby resulting in a substantial reduction of the data transfer rate.
On the other hand, with the method employing the recording pickup and the reproducing pickup, a reduction of the data transfer rate can be effectively avoided, but the overall construction becomes complicated because of the necessity of arranging the two optical pickups.
Further, with the method providing the defect detecting mechanism on the optical pickup, a reduction of the data transfer rate can also be effectively avoided, but the optical pickup has a complicated construction and the overall construction becomes complicated correspondingly.